If the STI Sport Muffler is too much money, here's a cheaper / ricer alternative: STI exhaust tips from the Levorg STI Sport. I bet it'll be on Japanparts soon.
[ame="https://www.youtube.com/watch?v=KiSxRRipqgw"]LEVORG STI Sport TVCM€Œ大ˆ‡な人とSTI€‡ 30’ - YouTube[/ame]
http://www.subaru.jp/levorg/stisport/